Large upstanding electrical equipments require support and damping means for reducing vibrations caused due to various reasons, for example, seismic vibrations, earthquakes, vibrations during operation of the equipment and other such shaking movements. Without sufficient damping and support, excessive motion of the vertical upstanding equipment, relative to the main base frame, could occur when the frequency of the ground motion is such as to cause amplification of the vertical upstanding equipment motion. Damping is one of many different methods that have been proposed for allowing a structure to achieve optimal performance when it is subjected to seismic, wind storm, blast or other types of transient shock and vibration like disturbances.
Devices for control of mechanical vibrations by use of dampers are known in the literature.
Prior art U.S. Pat. No. 3,973,078 is of interest with respect to this patent application. It discloses an energy absorbing device, such as a liquid filled vibration damper assembly, for preventing excessive relative motion between the lower supporting plate of the upstanding column, supporting electrical equipment, and the adjacent lower-disposed main supporting framework structure. Preferably, the energy absorbing device is a liquid filled dash-pot assembly which is utilized at one or more locations extending between the lower supporting plate member of each upstanding column structure and the lower disposed main supporting framework.
Prior art U.S. Pat. No. 3,911,199 is also of interest with respect to this patent application. It discloses a seismic motion-damper for upstanding electrical equipment comprising an inertia element disposed within a container containing a fluid liquid attached to an upper portion of upstanding electrical equipment. Said damper is tuned so as, by utilizing sympathetic vibrations, tends to cancel out seismic vibrations, which otherwise could damage the electrical equipment.
There still exists a need for a simpler, more robust and affordable damping solution for electrical equipment to protect it from vibrations.